Intro to Working Memory

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Are you really good at maths? Or do you consider yourself not so good? Have you ever wondered what it is that causes some people to excel with numbers while others struggle? While there are likely several factors that contribute towards someone’s mathematical ability or lack thereof, here at the MMAD Lab, we believe that working memory may be one of the factors that plays a key role.

First things first, what IS working memory? In simple terms, working memory can be described as holding short-term (i.e. temporary) information in your mind while using that information to accomplish a task. So, for example, if you asked someone for their phone number, they might tell you the first 3 digits and then pause while you type them into your phone. Those 3 digits are being held in your working memory temporarily until you accomplish the task of entering them into your contacts list. In this way, working memory is an active, temporary memory system that is analogous to the RAM in computers (in this analogy the computer’s hard drive would be the brain’s long-term memory).

An important characteristic to understand about working memory in humans is that it can only hold a limited amount of information. As one example of this, most people can only accurately hold about 7 numbers in working memory at any given time1. Another defining characteristic is that the information in working memory is transitory. It is only held briefly in order to attempt to accomplish a task or activity and then it is gone (unless other measures are taken to convert it into a more long-term memory).

Baddeley’s Model

It’s almost impossible to discuss working memory without mentioning Alan Baddeley’s model2. Baddeley is a research psychologist who created a framework to help conceptualise how working memory may operate in the brain. His model has come to be accepted by many as the de facto standard of working memory.

(Based on and developed from Baddeley, 2000).

In Baddeley’s model, working memory can be conceptualised as a mutli-store system (i.e. a system with several “containers” for storing temporary information). One of the “containers” is the phonological loop. The phonological loop is believed to hold speech and other auditory-based information. A second “container” is the visuo-spatial sketchpad which is believed to store visually presented information. Both of these are slave systems, that is they are subordinate to the central executive. The central executive, in this model,is the driving force behind the whole working memory system; it coordinates and controls the allocation and manipulation of information within and to the slave systems.

In an updated version of the model3 a further sub-component, the episodic buffer, was introduced. The episodic buffer can be thought of as a temporary interface between the two slave systems. In other words, it allows bits of information from the visuo-spatial sketchpad, the phonological loop, and long-term memory to be held temporarily and combined in this buffering space under the control of the central executive. This can allow things such as a sense of the order of events. The episodic buffer can both feed information into and retrieve information from episodic long-term memory and, thus, plays a critical step in long term episodic learning

Baddeley’s model of working memory was pioneering and very influencial. It has not been entirely without criticism though. In future articles, we will discuss other models of how working memory may work as well as exploring how working memory may affect mathematical abilities.